Semiconductor device and its manufacturing method

ABSTRACT

To improve the reliability and yield of a thin-type semiconductor device as used for a stack-type flash memory, the semiconductor device is manufactured by upheaving each of semiconductor chips (semiconductor devices) obtained by dicing a semiconductor wafer on an adhesive sheet from a backside via the adhesive sheet using an upthrow jig to which ultrasonic vibration is applied so as not to break through the adhesive sheet, and by picking up each semiconductor chip.

BACKGROUND OF THE INVENTION

The present invention relates to semiconductor device manufacturingtechnology.

A semiconductor device manufacturing process includes a first step ofsimultaneously forming a plurality of semiconductor chips on asemiconductor wafer, a second step of attaching an adhesive sheet to thesemiconductor wafer, a third step of dicing (cutting) the wafer and apart of the adhesive sheet so that the dies (the semiconductor chips)are not separated, and a fourth step of removing and picking up thecut-diced semiconductor chips from the adhesive sheet.

As a prior art in the fourth step, there are known JP-A-02-230754 (priorarts 1 and 2), JP-A-05-109869 (prior art 3), JP-A-06-295930 (prior art4), and JP-A-07-106363 (prior art 5).

Prior art 1 discloses a technique in which a needle pin is inserted froma backside of an adhesive sheet to be removed, so as to break throughthe adhesive sheet by the inserting force and further, the pin directlyupheaves a semiconductor chip to remove it from the adhesive sheet. Inprior art 1, large removal force is generated by directly upheaving thesemiconductor chip. Therefore, prior art 1 is regarded as a techniquecapable of performing the above operation more quickly and securely thanever before.

Prior art 2 discloses a technique in which a semiconductor chip isremoved from an adhesive sheet by adding ultrasonic vibration to theadhesive sheet while upheaving it using a rod pin to weaken the adhesiveforce between the semiconductor chip and the adhesive sheet. Thistechnique makes it possible to decrease the removal time by addingultrasonic vibration.

Prior art 3 discloses a technique similar to that of prior art 1, inwhich a semiconductor chip to be removed is directly upheaved using anupthrow needle by breaking through an adhesive tape. However, prior art3 is different from prior art 1 in the respect that the removal(peeling) of the semiconductor chip is made easy by using a plurality ofupthrow needles and adding vibration.

Prior art 4 discloses that the adhesive force between a semiconductorchip and an adhesive sheet is weakened by setting a removal head underthe adhesive sheet, which removal head comprises a bounding pin and aplurality of upthrow pins arranged around the bounding pin, to rub abackside of the adhesive sheet, two or three times, from the outsideusing the bounding pin via a mechanism such as a cam. Also, prior art 4discloses that after weaken the adhesive force, the semiconductor chipis uniformly lifted by raising the plurality of upthrow pins set aroundthe bounding pin together with the bounding pin to remove the adhesivesheet which has been weakened in adhesive force.

Prior art 5 discloses that after applying a dicing tape to the bottom bymeans of an upthrow rod and covering a die (semiconductor chip) with acollet, the dicing tape and the collet are vibrated by a vibrator inparallel with each other to remove an adhesive tape from thesemiconductor chip. The die is vacuumed into the collet and mounted onan island of a lead frame.

BRIEF SUMMARY OF THE INVENTION

Above prior art 1 has been frequently used so far in order to quicklyand securely perform the removal (peeling).

However, in the case of prior art 1, the adhesive sheet is brokenthrough by the needle pin to directly upheave the semiconductor chip andtherefore, a fine scratch is easily produced on a nonfunctional surface(an opposite surface of a terminal surface) of the semiconductor chip incontact with the adhesive sheet due to an impression of theneedle-shaped upthrow pin.

In recent years, a memory module is increased in capacity and a systemLSI is improved in performance, so that a semiconductor chip isdecreased in thickness and size. Particularly in the case of a mobileterminal such as a cellular phone, a stack-type flash memory isfrequently used, in which many large-capacity storage devices arestacked and moreover, a central processing unit is stacked.

In the case of the semiconductor chip as applied to the above stack-typesemiconductor device, it is necessary to set the thickness of thesemiconductor chip to 100 μm or less in order to decrease the thicknessof the semiconductor device.

However, in the case of applying prior art 1 to manufacturing of asemiconductor device on which the thin semiconductor chip of 100 μm orless is mounted, remarkable troubles are occurred because of thefollowing reasons.

According to experiments by the inventors, when performing removal(peeling) using prior art 1 under mass production condition, a scratchon a backside of a semiconductor chip may reach 30 μm in depth. Thescratch of this degree does not matter in the case of a conventionalsemiconductor chip having a thickness of 200 μm or more because thethickness of an insulating layer up to a functional surface on which aterminal is formed is large. However, in the case of a thinsemiconductor chip of 100 μm or less as used for a stack-type flashmemory, the scratch affects a place very close to the functionalsurface. When mounting the semiconductor chip on a substrate or leadframe, a predetermined strength of the semiconductor chip cannot besecured or the semiconductor chip is cracked due to the scratch.

Accordingly, it is necessary to improve the reliability of a stack-typesemiconductor device.

Also, the same problem occurs depending on the structure or purpose ofthe semiconductor device (semiconductor package).

Firstly, the depth of a scratch on a backside of a semiconductor chipallowable in view of strength according to a package structure and asemiconductor chip thickness is described below.

In the case of flip chip mounting (FC), a semiconductor chip is directlymounted on user's circuit board. Therefore, the semiconductor chip isexposed and thus easily receives an external force. If there is a damagesuch as an impression or scratch of a depth which cannot be ignored inconnection with the thickness of the semiconductor chip, the mechanicalstrength of the semiconductor chip is extremely deteriorated due to theexternal force. Particularly in a process from manufacturing to shipmentor a process before mounting on user's circuit board, the external force(pressure or impact) is applied. Moreover, even when an end product iscompleted, destruction is caused due to change in working temperature,and the deflection or the external force due to impact.

Also, a structure using chip-on-board mounting (COB) is molded andcovered with a resin so as to cover the whole semiconductor chip aftermounting the semiconductor chip on user's circuit board. In this case,even if the mechanical strength is deteriorated due to presence of animpression or scratch on the semiconductor chip, the semiconductor chipmounted on the circuit board is protected by the resin mold and thereby,the probability of breakage is small after the chip becomes an endproduct. However, in the process from the manufacturing to the shipmentof the semiconductor chip and in the process before the chip is mountedon user's circuit board, the semiconductor chip is not protected andtherefore, the probability of breakage is not reduced. The probabilityof breakage at the manufacturing stage can be reduced by reducing impactwhen transferring the chip to a tray, by relaxing impact when carryingthe chip by improving a packaging material, and by process control inthe circuit mounting process because the process control is easy incomparison with the case of the end product. However, there increaseadministrative restrictions and thus make the handling difficult.

Further, in the case of a semiconductor device packaged by a mold, asemiconductor chip is already covered with a mold material such as aresin when the semiconductor device is shipped from a semiconductormaker. Therefore, a scratch is hard to matter even in the case of a thinsemiconductor chip. Furthermore, because the manufacturing process isconsistently under control by a semiconductor maker, it is easy to makesevere process control. Therefore, the semiconductor device packaged bythe mold can use a thin semiconductor chip even if having a scratch ofthe same degree.

However, also in this case, the semiconductor chip may be broken by ascratch in the process before packaging the semiconductor chip, bynecessity. Therefore, a technique for reducing the scratches isnecessary.

Moreover, the restriction of the thickness of the semiconductor chipusable in a prior art varies also in accordance with the use conditionof the end product, in addition to these mounting embodiments. Forexample, in the case of a toy, the temperature and humidity rangesguaranteeing its performance, the shock resistant performance, and theguaranteed service life are slight, and a requirement for strength andreliability is not severe, in comparison with the case of thesemiconductor used in typical industrial applications. Therefore, aproblem may not occur even if using the toy in a slight protecting statein comparison with the case of the industrial semiconductor chip. Aswith the case with the above, in the case of an electronic informationunit attaching importance to small size and weight such as a cellularphone and a mobile unit, a requirement for reliability may be reducedfor the weight reduction purpose. However, a defect due to the abovescratch becomes an issue if each product exceeds a certain limitalthough there is a difference between degrees.

FIG. 17 shows limit values of the applicable thicknesses of thesemiconductor chips corresponding to various mounting conditions andapplications in the case that the semiconductor chip is fabricated in aprocess in which an impression and scratch may occur on the backside ofthe semiconductor chip due to the above prior art.

As already described, in the case of FC, it is necessary to use a thicksemiconductor chip because the semiconductor chip is only slightlyprotected. In the case of the mold type, breakage or trouble does noteasily occur even if using a thin semiconductor chip because of theprotective effect by the mold. However, when using conventional removaltechnique, an impression or scratch due to the impression may occur on abackside of a semiconductor chip. Therefore, it is generally difficultto use a thin semiconductor chip of 100 μm or less. Even if severelymanaging the manufacturing process and improving a mounting structure,the conventional removal technique is difficult to make greatimprovement to satisfy the illustrated applicable limits.

In the case of prior art 3, a functional surface of a semiconductor chipis easily scratched since a needle upthrow pin is used for the removal,as with the case with prior art 1. Moreover, because vibration isapplied, generation of an impression on a backside of the semiconductorchip is also progressed. Even if no trouble occurs in the case of ageneral-purpose semiconductor chip having a thickness of approx. 200 μm,when using a thin semiconductor chip of 100 μm or less, the probabilityof causing a critical trouble with respect to strength reduction islarge.

Prior art 2 discloses that the adhesive sheet on the backside of thesemiconductor chip is removed by pressing it against a vibrator having aflat tip end.

However, the thickness of the semiconductor chip to be removed in priorart 2 is 575 μm. In the case of the semiconductor chip having the abovethickness, the influence of the above scratch is small. Therefore, priorart 1 having a high removal speed has been applied thereto so far.

That is, a problem to be solved by the technique of prior art 2 is notknown as to whether a remarkable effect can be obtained in asemiconductor chip having any thickness or not. Therefore, prior art 2has not been applied in the semiconductor industry.

Although there are many other removal techniques, it has been said thata method of breaking through an adhesive sheet by a tip end of a needleupthrow pin is the most preferable conformation for practical use suchas prior art 1 and prior art 3, in the semiconductor industry.

In other words, it has not been studied what removal method is suited toremove an adhesive sheet attached to a semiconductor chip having athickness of 100 μm or less made by back-grinding, as used for astack-type semiconductor device.

It is an object of the present invention to provide a semiconductordevice manufacturing method for quickly removing an adhesive sheetattached to a semiconductor chip having a thickness of 100 μm or lesswithout scratching the semiconductor chip.

Moreover, it is another object of the present invention to provide asemiconductor device manufacturing method for quickly removing anadhesive sheet attached to a semiconductor chip used for a stack-typesemiconductor device without scratching the semiconductor chip.

The present application includes a plurality of inventions capable ofsolving the above problems.

Typical ones of the inventions are described below.

One of the inventions is a semiconductor device manufacturing method formanufacturing a semiconductor device by dicing a semiconductor wafer towhich an adhesive sheet is attached into individual semiconductor chips,vacuuming and holding each semiconductor chip by a vacuuming jig,collecting the semiconductor chips from the adhesive sheet to use thesemiconductor chips, wherein when removing the adhesive sheet from asemiconductor chip having a thickness of 100 μm or less, ultrasonicvibration is applied to the semiconductor chip via the adhesive sheet.

Because the ultrasonic vibration is used, it is possible to remove thesemiconductor chips from the adhesive sheet without breaking through theadhesive sheet. Accordingly, because it can be possible to use asemiconductor chip hardly damaged in the region of a functional surface,it is possible to provide a semiconductor device having highreliability.

Moreover, there is a stack-type semiconductor device on which asemiconductor chip is vertically mounted, which uses the semiconductorchip removed, by means of ultrasonic vibration, from an adhesive sheetattached to the semiconductor chip subjected to a back-grinding step anda dicing step.

Further, a semiconductor chip applied to a stack-type semiconductordevice has a very small thickness of 100 μm or less. Therefore, ifapplying a semiconductor chip manufactured by a conventional method, acrack occurs when actually mounting it and thus, the reliability is low.However, if using a semiconductor chip manufactured by removal using anultrasonic wave, it is possible to provide a semiconductor device havinghigh reliability because the number of cracks is very small.

Other objects, features, and advantages of the present invention willbecome more apparent from the description of the embodiments of thepresent invention relating to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows sectional views illustrating a semiconductor wafer backsidegrinding step and a dicing step in order of steps;

FIG. 2 is a sectional view showing an example of a configuration of achip separating unit;

FIG. 3 shows sectional views illustrating an upthrow operation of thechip separating unit in order of steps;

FIG. 4 is an enlarged sectional view showing a state of an adhesivelayer at the time of upthrowing in the chip separating unit;

FIG. 5 shows sectional views illustrating an example of an shape of atip end of an upthrow jig of the chip separating unit;

FIG. 6 shows views illustrating an example of the size of the tip end ofthe upthrow jig of the chip separating unit;

FIG. 7 shows sectional views illustrating an example of a tip end shapeof a vacuuming collet;

FIG. 8 shows sectional views illustrating an example of the arrangementof vacuuming holes of the vacuuming collet;

FIG. 9 is a timing chart showing an example of linked operations ofvarious parts of the chip separating unit;

FIG. 10 is a sectional view showing a conformation of a chip separationdefect prevention means to be applied to the chip separating unit;

FIG. 11 is a sectional view showing a conformation of a chip separationdefect prevention means to be applied to the chip separating unit;

FIG. 12 is a sectional view showing a chip separating unit used for asemiconductor device fabrication method;

FIG. 13 is a sectional view showing a chip separating unit;

FIG. 14 is a sectional view showing a chip separating unit;

FIG. 15 is a sectional view showing a chip separating unit;

FIG. 16 shows views illustrating an example of an upthrow-jig movingtrack;

FIG. 17 is an illustration showing limit values of applicablesemiconductor chip thicknesses in correspondence with various mountingconformations and applications in the case of fabricating thesemiconductor chip by a process in which impressions and scratches mayoccur on a backside of the semiconductor chip;

FIG. 18 is an illustration showing an example of a relation between theultrasonic wave applying time and the upheaving amount of an upthrow jigwith respect to the size of a semiconductor chip;

FIG. 19 is an illustration showing an example of a relation between afrequency and an amplitude of the ultrasonic wave vibration;

FIG. 20 is a sectional view showing an example of a configuration of achip separating unit;

FIG. 21 shows sectional views illustrating an upthrow operation of achip separating unit;

FIG. 22 is a sectional view showing a chip separating unit;

FIG. 23 is a sectional view showing a chip separating unit;

FIG. 24 shows sectional views illustrating an example of an upthrowoperation in order of steps;

FIG. 25 is a sectional view showing a chip separating unit;

FIG. 26 shows sectional views illustrating an example of an upthrowoperation in order of steps;

FIG. 27 is a sectional view showing a chip separating unit;

FIG. 28 is a sectional view showing a chip separating unit; and

FIG. 29 shows top views illustrating an example of actions of a chipseparating unit.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described in detail belowby referring to the accompanying drawings.

FIGS. 1(a) to 1(e) are sectional views showing an example of a waferback grinding step and a dicing step in a semiconductor devicefabrication method, in the order of the steps, in which a semiconductorwafer is processed to be thin, and cut into semiconductor device units.

A semiconductor device fabrication flow of the present invention isdescribed below by referring to FIG. 1.

At present, silicon is most frequently used as a semiconductor material.A silicon wafer is formed by grinding, slicing and polishing the outerperiphery of ingot-shaped single-crystalline silicon.

Then, a plurality of semiconductor circuits of chip units aresimultaneously formed on a semiconductor wafer in accordance with thenormal semiconductor fabrication method of a wafer process such as thephotolithography technique.

A semiconductor wafer 1 in which semiconductor circuits are formed isdecreased in thickness into a predetermined thickness of approx. 200 μmby attaching an adhesive tape 40 for grinding to the circuit face sideand grinding the wafer back 1 a by a grinder 41 (FIG. 1(a)) to obtain apredetermined thickness of the wafer. The wafer back 1 a whose surfacebecomes rough and warped due to grinding is finished into apredetermined thickness of 100 μm or less by a chemical etchingapparatus 42 or polishing apparatus (FIG. 1(b)). Then, non-defectiveproduct sorting is performed through a functional test of eachsemiconductor device by a wafer probe at a wafer level (for example, byputting a mark on a defective semiconductor chip and thereby makingexternal sorting possible).

The semiconductor wafer 1 decreased in thickness is attached to anadhesive sheet 5 for dicing so that a semiconductor circuit pattern isturned upward.

The adhesive sheet 5 is formed by an elastic resin sheet base material 4such as PVC (polyvinyl chloride) or PET (polyethylene terephthalate) andan adhesive agent layer 3 at one side of the sheet base material. Theadhesive agent layer 3 includes a layer which is cured throughirradiation with ultraviolet radiation (UV) and its adhesive strength isdeteriorated. The adhesive sheet 5 to which a semiconductor wafer isattached is fixed by extending and bonding it to a frame 7 so that itsouter periphery is not loosened (FIG. 1(c)).

The semiconductor wafer 1 attached to the adhesive sheet 5 fixed to theframe 7 is longitudinally and transversely diced along a cut margin(scribing line) of approx. 100 μm at peripheral four sides of asemiconductor device 2 (semiconductor chip) by using a very thincircular blade to which fine diamond particles are attached, as referredto as a dicing saw 43, to cut the semiconductor wafer 1 intosemiconductor chip units in a dicing step (FIG. 1(d)).

UV is applied from the back of the adhesive sheet 5 of the cutsemiconductor chips 2 to cure the adhesive agent layer 3 of the adhesivesheet 5 and reduce its adhesive strength so that the semiconductor chips2 can be easily separated from the adhesive sheet 5 (FIG. 1(e)).

Then, an external inspection is performed by a microscope and, cracksand scratches are checked to remove or mark defective chips.

After the dicing step, semiconductor chips are separated like eachembodiment of the present invention shown below to selectively pick uponly a non-defective semiconductor device (semiconductor chip 2) freefrom a defective mark. Then, the picked-up semiconductor device isbonded to a substrate on which the semiconductor device is to bemounted, such as a lead frame, by a bonding device. To join the devicewith the substrate on which the device is to be mounted, there is amethod for previously applying an adhesive resin such as silver paste tothe substrate on which the device is to be mounted before bonding toslightly press a chip onto the substrate, or a method for joining a chipon which a backside a gold thin film is formed with a silver-platedsubstrate on which a device is to be mounted by making eutectic crystalof gold and silicon at a high temperature.

Then, wire bonding is performed, in which an external electrode pad ofthe semiconductor chip and a mounted substrate-side lead electrode areconnected each other by a gold wire. As other methods, there are thermalsolder reflow in which a solder bump or gold bump is previously formedon an external electrode pad of a chip to align the bump with a leadelectrode, flip-chip bonding in which joining is performed by applyingultrasonic vibration in a pressurized state, and a TAB method in which abump is formed on an external electrode pad of a chip or a tape film andpressurized and heated to perform joining.

Moreover, a semiconductor chip, gold wire, and their joined portions areresin-sealed in order to electrically and mechanically protect them froman external environment.

Furthermore, in the case of a lead frame, the tip end of a lead is cutand then, the lead is curved by a roller to mold the lead frame so thatthe lead frame is finished.

Furthermore, non-defective semiconductor devices are shipped afterpassing through a non-defective product sorting step (aging etc.) beforeshipment.

In addition to the above mounting methods, after the dicing step, thereis a case in which a chip to be shipped is mounted on a chip mountingvessel (tray) in which recesses larger than the chip shape are arrangedat a grid or a film having a small adhesive strength by a chipseparating unit and a bonding unit having a pickup of each embodiment ofthe present invention shown below and shipped.

FIG. 2 is a sectional view showing an example of the configuration of achip separating unit used for a fabrication method of a semiconductordevice which is this embodiment 1.

FIGS. 3(a) and 3(b) are sectional views showing an example of theupthrow operation of the chip separating unit of this embodiment 1 inorder of the steps.

FIG. 4 is an enlarged sectional view showing an example of a state of anadhesive agent layer at the time of upthrowing by the chip separatingunit of this embodiment 1.

The chip separating unit of this embodiment 1 has a pickup stage 8 forsupporting the adhesive sheet 5 to which the semiconductor chip 2 havingbeen subjected to a dicing step is attached and the frame 7 to performhorizontal movement and positioning operation, a vacuuming stage 15located under the pickup stage 8 to vacuum the back of the adhesivesheet 5, an upthrow jig 11 which is a jig for upthrowing the adhesivesheet 5 and semiconductor chip 2 and which is vertically movably set toan upthrow hole 13 at the center of the vacuuming stage, an ultrasonicvibrator 17 having a built-in piezoelectric device 18 arranged under theupthrow jig 11, and a vacuuming collet 16 which is a member forgenerating supersonic vibration in the upthrow jig 11 and for vacuumingand holding the separated semiconductor chip 2 and mounting the chip 2on a substrate and which is set above the pickup stage 8.

As shown in FIG. 3(a), the semiconductor chip 2 to be separated isupheaved by the tip end of the upthrow jig 11 through the adhesive sheet5 by vacuuming the back of the sheet 5 by the vacuuming stage 15 andraising the upthrow jig 11 while holding the sheet 5. In this case, theadhesive sheet 5 is extended, so that a tension is generated. Theupheaving amount of the upthrow jig 11 is set to approx. 0 to 0.5 mm onthe basis of the upside of the vacuuming stage 15 so as not to break theadhesive sheet 5. However, the upheaving value of the upthrow jig ischanged in accordance with the size of the adhesive sheet 5 orsemiconductor chip 2 used but it is not restricted to a value other thanthe above upheaving value.

After raising the upthrow jig 11 up to a predetermined value, thesemiconductor chip 2 is separated from the adhesive sheet 5 by providingultrasonic vibration in the direction vertical to the chip 2 so that thetip end of the upthrow jig 11 has a frequency of 10 to 100 kHz and anamplitude of 5 to 100 μm and providing ultrasonic vibration for thesemiconductor chip 2 through the adhesive sheet 5.

In this case, according to experiments by the present inventors, asshown in FIG. 19, when a frequency and an amplitude are too large, theheat due to the ultrasonic vibration by the upthrow jig 11 is increasedwhile the time required for separation is short to dissolve the adhesivesheet. However, when the frequency and amplitude are too small, theadhesive sheet is not be dissolved but the time required for separationis increased and thus, this is not practically used.

Therefore, in the case of the frequency and amplitude of the ultrasonicwave, a frequency of 20 to 80 kHz and an amplitude of 20 to 80 μm arepractical-use values.

When upheaving the semiconductor chip 2 by the upthrow jig 11 throughthe adhesive sheet 5, a tension is generated in the base material 4 ofthe adhesive sheet 5, the adhesive agent layer 3 at the boundary betweenthe sheet base material 4 and semiconductor chip 2 is also expanded, andan adhesive agent layer 3 a on the outer periphery of the semiconductorchip 2 is most expanded (FIG. 4). When vertically vibrating the upthrowjig 11 at a high speed under the above state, the adhesive agent layer 3is repeatedly expanded and contracted at a high speed, a fatigue failureoccurs in the adhesive agent layer 3, the failure progresses, and thesemiconductor chip 2 is separated from the adhesive agent layer 3.

Moreover, by providing the ultrasonic wave for the upthrow jig 11, theupthrow jig 11 is heated up to several tens of degrees. However, bypressing the tip end of the heated upthrow jig 11 against the adhesivesheet 5 to which a semiconductor chip to be separated is attached, theadhesive sheet 5 is expanded and contracted, so that the semiconductorchip 2 is easily removed.

As shown in FIG. 3(b), when picking up the semiconductor chip 2, theseparated semiconductor chip 2 previously moves the vacuuming collet 16to a predetermined height at the immediately upper portion of thesemiconductor chip 2 to be previously removed, and lowers and positionsthe collet 16, and the semiconductor chip 2 is vacuumed and held by theturned-on vacuuming collet 16 and mounted on a substrate.

The vacuuming collet 16 is turned down at a height, for example, up toapprox. 0 to 0.1 mm from the upside of the semiconductor chip, so as notto contact with but come close to the upside of the semiconductor chip 2when upthrowing the semiconductor chip 2 by the upthrow jig 11.

Thus, by using a chip separating unit to which the ultrasonic vibrationare added, it is possible to obtain a thin semiconductor device havingno scratch on the back of a semiconductor chip without breaking anadhesive sheet.

The semiconductor chip 2 attached on the adhesive sheet 5 fixed to theframe 7 is fixed to the pickup stage 8. The pickup stage 8 is supportedby a two-shaft horizontal movement mechanism (not illustrated) to bemovable so that the semiconductor chip 2 to be separated comes to theimmediately upper portion of the upthrow jig 11.

Moreover, when upheaving the semiconductor chip 2 by the single upthrowjig 11, the center of the semiconductor chip 2 is generally upheaved bythe tip end of the upthrow jig 11, as shown in FIG. 2 and FIG. 3.However, it is also allowed to move and position the pickup stage so asto upthrow the vicinity of a corner of the semiconductor chip 2 by theupthrow jig 11 in accordance with the chip separation theory previouslydescribed.

A plurality of vacuuming grooves 14 and a plurality of holes 24communicating with an external vacuuming mechanism such as a vacuum pump(not illustrated) are formed on the upside of the vacuuming stage 15facing the back of the adhesive sheet 5, so that the adhesive sheet 5can be vacuumed and held and the vacuum cancel operation can beperformed around the vacuuming grooves 14 and holes 24.

An upthrow hole 13 through which the upthrow jig 11 can be verticallymoved is opened at the inside of the vacuuming grooves 14 and holes 24of the vacuuming stage. The size and shape of the upthrow hole 13 arechanged in accordance with the aperture size and shape of the tip of theupthrow jig 11, and the size of the semiconductor chip 2 to beseparated. However, when a chip size is used as a reference, forexample, when separating a square semiconductor chip 2, a hole is formedinto a circular hole equal to or less than the diagonal length of thesemiconductor chip 2 so that the chip does not fall into the upthrowhole 13. When separating a rectangular semiconductor chip 2, a slottedhole smaller than the chip size is preferable.

The vacuuming grooves 14 and vacuuming holes 24 formed at the outside ofthe upthrow hole 13 are formed into a shape or arrangement at which avacuum state is kept so that a vacuum state is kept when upheaving theadhesive sheet 5 to which a semiconductor chip 2 not intended to beseparated is attached by the upthrow jig 11 for example, or at which alarge load such as a crack or fissure is not applied to the chip whenvacuuming the adhesive sheet. Moreover, it is possible to use a methodfor vacuuming the adhesive sheet 5 in which innumerable vacuuming holesare formed outside of the upthrow hole 13.

FIG. 5 is a sectional view showing an example of an upthrow-jig tip-endshape of the chip separating unit of this embodiment 1, and FIGS. 6(a)and 6(b) are illustrations respectively showing an example of the sizeof the tip end of the upthrow jig of the chip separating unit of thisembodiment 1.

The ultrasonic vibrator 17 to which the upthrow jig 11 is set issupported by a vertical movement mechanism section 21. Moreover, thevibrator 17 has a structure independent of the vacuuming stage 15 andmakes it possible to perform the operation for upthrowing the adhesivesheet back 5 of the semiconductor chip 2 on the upthrow hole 13 byvertically moving the upthrow jig 11 and ultrasonic vibrator 17.Furthermore, the piezoelectric device 18 for generating vibration isbuilt in the ultrasonic vibrator 17, an ultrasonic oscillator (notillustrated) is connected to the piezoelectric device 18 and the upthrowjig 11 ultrasonic-vibrates in accordance with the on/off operation ofthe oscillator. The upthrow jig 11 and ultrasonic vibrator 17 are fixedby screws. When changing the shape and size of the tip end of a jig andthe amplitude condition of the ultrasonic vibration in accordance withthe size of a chip to be separated and adhesive sheet characteristic, itis possible to easily replace the upthrow jig 11.

The shape of the tip end of the upthrow jig 11 contacting with the backof the adhesive sheet 5 is formed into a spherical surface so as not tobreak the adhesive sheet in the case of a very small semiconductor chipof approx. 0.5-mm square (FIG. 6(a)). It is allowed to change Rdimension of the spherical surface and the shape of the jig inaccordance with the size of a chip to be removed and the characteristicof an adhesive sheet.

A large-area semiconductor chip such as a chip of 1 mm square or more isformed into the flat type same as the chip shape so that the heat due toultrasonic vibration and the internal friction heat of an adhesive sheetcaused by the ultrasonic vibration is effectively propagated to thewhole adhesive face to which a semiconductor chip is attached in a shorttime (FIG. 5(b)). Because the edge portion 11 a of the tip end may breakthe adhesive sheet, it is preferable to apply C chamfering (FIG. 5(c))or R chamfering (FIG. 5(d)) to the edge portion 11 a. Moreover, it ispossible to use a spherical surface. It is also allowed to change thechamfering dimension and jig shape in accordance with the size of a chipto be separated and the characteristic of an adhesive sheet. It ispreferable that the aperture dimension of the upthrow jig, in the caseof a quadrangle, is a quadrangle W2 smaller than a chip size W1 of thesemiconductor chip so that the adhesive agent layer at the outerperiphery of the chip is expanded and the ultrasonic vibration ispropagated to the outer periphery of the chip (FIG. 6(a)) in accordancewith the chip separation theory shown in FIG. 4. Moreover, in the caseof a circle, a diameter W4 is preferable, which is smaller than a chipdiagonal length W3 in view of the same consideration as the case withthe square (FIG. 6(b)).

In the case of this embodiment 1, a chip separation to which theultrasonic vibration is added is performed in accordance with thevertical movement of the single upthrow jig 11. Therefore, for example,only by changing the shape and aperture dimension of the upthrow jig 11in accordance with the size of the semiconductor chip 2, this can beapplied to all type of pickup of the semiconductor chips 2, from acomparatively-large semiconductor chip 2 to a very small semiconductorchip 2 having one side of several millimeters or less, and it ispossible to obtain a semiconductor device constituted by thesemiconductor chip 2 of all sizes having no scratch on the back of thechip. Moreover, in the case of this embodiment, a chip is separated by asingle upthrow jig. However, in the case of a large semiconductor chipor a rectangular semiconductor chip, it is allowed to use a chipseparating unit for separating the semiconductor chip 2 by using aplurality of upthrow jigs.

There are many types of the adhesive sheet 5 to which the semiconductorchip 2 is attached, which are selected in accordance with the purpose.The adhesive sheet 5 suitable for the chip separating unit of embodiment1 of the present invention shown in FIG. 2 and 3, namely, the sheet basematerial 4 depends on a chip size.

According to experiments by the present inventors, in the case of a verysmall chip of 0.5-mm square or less, an easily-extendable base materialsuch as PO (polyolefin) can be stably separated. This is because thesheet base material uses a not-easily extended material such as PET orPVC which is a rigid plastic and thereby easily propagates vibration,and the influence of an ultrasonic wave is widened and therefore, anadjacent chip is separated together. However, when the base materialadopts PO, it does not easily propagate the vibration because it is anelastomer. Therefore, it does not easily influence the adjacent chips.Moreover, in the case of a large-area chip of 1-mm square or more, it ispossible to more stably separate a not-easily-extended chip basematerial. As previously described, when a sheet base material adopts anot-easily-extendable material such as PET or PVC, the adjacent chipsare not separated together because the vibration is easily propagatedthrough PET or PVC, and a large-area chip has a large adhesive area.

Moreover, when an adhesive sheet is loosened, it is not easily removedbut when a tension is applied to the extendable adhesive sheet, thesheet is easily separated. Therefore, it is allowed to set an expandingmechanism (not illustrated) for uniformly extending the adhesive sheet 5to the pickup stage 8 of the chip separating unit shown in FIG. 2.

Thus, by selecting a sheet base material of an adhesive sheet suitablefor a chip size, it is possible to obtain a chip separating unit freefrom a separation error.

FIGS. 7(a) and 7(b) are sectional views respectively showing an exampleof the tip end shape of a vacuuming collet, and FIGS. 8(a) and 8(b) aresectional views respectively showing an example of arrangement ofvacuuming holes of a vacuuming collet.

The vacuuming collet 16 of the chip separating unit shown in FIG. 2 issupported by two-axes movement mechanism sections 22 and 23 so as tomake it possible to be moved and positioned to a position immediatelyabove the semiconductor chip 2 attached to the adhesive sheet 5supported by the frame 7 and carry the vacuumed and held semiconductorchip 2 to the outside.

A vacuuming hole 16 a communicating with an external vacuuming mechanismsuch as a vacuum pump (not illustrated) is opened on the vacuumingcollet 16 to make it possible to vacuum and hold the separatedsemiconductor chip 2 and stop holding of the chip 2.

As shown in FIG. 7, the shape of the vacuuming collet 16 for vacuumingand holding the semiconductor chip 2 generally includes a flat collet(FIG. 7(a)) for vacuuming a semiconductor chip by contacting with theupside of the chip, or a conical collet (FIG. 7(b)) for positioning asemiconductor chip with the outer periphery of the chip and vacuuming itwhen preventing a collet from contacting with the upside (circuitpattern face) of the semiconductor chip (FIG. 7(b)) and one of the bothtypes is selected in accordance with a semiconductor chip to beseparated.

To vacuum and hold the semiconductor chip 2 by the vacuuming collet 16,when the vacuuming hole 16 a to be vacuumed to the upside of the chip islarge, the chip is warped at the portion of the hole and in the worstcase, the chip may be broken. The diameter of the vacuuming hole 16 a ofthe vacuuming collet 16 contacting with the chip 2 is set to a diameterat which the chip is not deformed when vacuumed, for example, the holediameter d is set to approx. 0.2 mm. In the case of a very small chip ofapprox. 0.5-mm square, it is enough to use one vacuuming hole as sown inFIG. 7(a). Moreover, when vacuuming a large-area chip of 1-mm square ormore, the diameter d of the vacuuming hole contacting with the chip isset to approx. 0.2 mm as shown in FIG. 3(b) as previously described andit is preferable to use the number of vacuuming holes suitable for thechip area and form the vacuuming holes at a grid (FIG. 8(a)), staggered(FIG. 8(b)), or random arrangement.

Moreover, the tip end dimension D of the vacuuming collet to be vacuumedby a semiconductor chip is set to a size approximately equal to the sizeof the chip to be separated.

As a material of the tip end of the vacuuming collet 16 contacting witha chip, there are abrasion-resistant resin such as VESPEL material,electrostatic-resistant resin such as acetal copolymer, rubber having acushioning characteristic, and metal. However, one of these substancesis selected in accordance with the semiconductor chip 2 to be separatedor a separating condition.

FIG. 9 is a timing chart showing an example of linked operations ofvarious portions of the chip separating unit of this embodiment 1.

In FIG. 9, a graph 41 shows the vacuuming timing of a vacuuming collet,graph 42 shows the position of the height of a collet, graph 43 showsthe upperside position of a chip, graph 44 shows the position of anupthrow jig, and graph 45 shows ultrasonic-wave applying timing.

The timing and applying time T for applying the ultrasonic vibration toan upthrow jig is approx. 0.05 to 5 sec. as an example as shown by thegraph in FIG. 9.

According to experiments by the present inventors, in the case of a verysmall semiconductor chip of 0.5-mm square or less, the applying time isshort because the adhesive area is small and the chip can besufficiently separated for approx. 0.1 sec from the viewpoint of eachsize of a chip to be separated. However, in the case of a large-areasemiconductor chip of 1-mm square or more, because the adhesive area islarge, the chip is separated for 0.1 to 2 sec. As the chip areaincreases, the applying time increases. It is possible to set theapplying start timing so that applying is started before or afterupthrowing by an upthrow jig as shown by the graphs 45 and 45 a.

FIG. 18 is a graph showing experiment results of the ultrasonic waveapplying time and the upheaving value of an upthrow jig with respect toevery size of the semiconductor chip 2. Values of the experiment resultsare changed in accordance with the characteristic of the adhesive sheet5 used and the aperture dimension and shape of the tip end of theupthrow jig 11.

Moreover, while not illustrated in FIG. 9, it is allowed to separate thesemiconductor chip 2 in accordance with the operation sequence ofapplying ultrasonic vibration to the upthrow jig 11 while making therising operation of the upthrow jig 11 synchronize with that of thevacuuming collet 16 by raising the upthrow jig 11 and lowering thevacuuming collet and thereby holding the semiconductor chip 2 to beseparated and the adhesive sheet 5.

By using a chip separating unit to which the above ultrasonic vibrationis added, it is possible to obtain a thin semiconductor device having noscratch on the back of a semiconductor chip without breaking an adhesivesheet.

FIG. 10 is a sectional view showing conformation 1 of imperfect chipseparation preventive means in the chip separating unit of thisembodiment 1.

When separating the semiconductor chip 2 by using the chip separatingunit of this embodiment 1, it is allowed to use a means for measuringthe temperature produced when applying ultrasonic vibration to theupthrow jig 11 and for controlling the temperature.

The chip separating unit shown in FIG. 10 separates the semiconductorchip 2 in accordance with the operation procedure of the chip separatingunit of this embodiment 1. The semiconductor chip 2 to be separatedvacuum-sucks the sheet backside by the vacuuming stage 15, raises theupthrow jig 11 while holding the adhesive sheet 5, and upheaves thesemiconductor chip 2 through the adhesive sheet 5. After upheaving thesemiconductor chip 2, the semiconductor chip 2 to be removed appliesultrasonic vibration to the upthrow jig 11.

In this case, a means 31 for measuring the tip-end temperature of theupthrow jig 11 generated due to the ultrasonic vibration, a means 32 formeasuring the temperature of the semiconductor chip 2 to be separated,and a means 33 for measuring the temperature of the adhesive sheet 5 atthe portion to which the chip to be separated is attached are used tomeasure the temperature of each portion when the ultrasonic wave isapplied. By adding the heat of allowable limit or more to thesemiconductor chip 2, the circuit of the semiconductor chip 2 is broken.Moreover, when adding excessive heat to the adhesive sheet 5, theadhesive sheet 5 is melted and the melted adhesive sheet 5 or adhesiveagent layer 3 may be attached to the backside of the semiconductor chip2. Furthermore, when the adhesive sheet 5 is melted, the backside of thesemiconductor chip 2 is exposed, and when the upthrow jig 11 contactswith the backside of the semiconductor chip 2, the backside of thesemiconductor chip 2 is scratched. For these prevention measures forimperfect chip separation, a function is set, which automatically ormanually adjusts the applying time of an ultrasonic wave and theupheaving value of the upthrow jig 11 so that a temperature equal to orhigher than a predetermined temperature is not produced in each of theabove portions in accordance with a measured value obtained by directlyor indirectly measuring temperatures of the tip end of the upthrow jig11, the semiconductor chip 2 to be separated, and adhesive sheet 5 andupthrowing them in a controller 30 together. If necessary, it is allowedto set radiation means to the tip end of an upthrow jig or a cooling fanto reduce heat to be produced.

Thus, by measuring the temperature produced by applying the ultrasonicvibration and setting a function for controlling the temperature, it ispossible to obtain a thin semiconductor device having no imperfectseparation.

FIG. 11 shows a sectional view of the chip separating unit of thisembodiment 1 to which an imperfect chip separation prevention means isadded.

When separating the semiconductor chip 2 by using the chip separatingunit of this embodiment 1, it is allowed to use a means for measuringthe tension of the adhesive sheet 5 produced when upheaving thesemiconductor chip 2 by the upthrow jig 11 through the adhesive sheet 5and applying ultrasonic vibration to control the tension of the adhesivesheet.

The chip separating unit shown in FIG. 11 separates the semiconductorchip 2 in accordance with the operation procedure of the chip separatingunit of this embodiment 1. The semiconductor chip 2 to be separated isupheaved through the adhesive sheet 5 by vacuuming the sheet backside bythe vacuuming stage 15, raising the upthrow jig 11 while vacuuming andholding the adhesive sheet 5, and upheaves the semiconductor chip 2.After the semiconductor chip 2 is upheaved, ultrasonic vibration isapplied to the upthrow jig 11. In this case, a tension is produced inthe adhesive sheet 5 by upheaving by the upthrow jig 11 and theamplitude of the ultrasonic vibration and the semiconductor chip 2 isdeflected. When the upthrow value of the upthrow jig 11 and theamplitude of ultrasonic vibration are large, the deflection of thesemiconductor chip 2 is also increased. In the worst case, fissures orcracks occurs on the semiconductor chip 2. Moreover, the deflection ofthe semiconductor chip 2 depends on the vacuuming pressure 15 a of thevacuuming stage 15 for vacuuming and holding the adhesive sheet 5. Thedeflection of the semiconductor chip 2 also depends on the position atwhich the semiconductor chip 2 is upheaved by the upthrow jig 11. Forthese prevention measures of imperfect chip separation, a function isset, which automatically or manually adjusts the upthrow value of theupthrow jig 11, vacuum pressure 15 a of a vacuuming stage, or positionsof the semiconductor chip 2 and upthrow jig 11 so that an excessivetension is not produced in the adhesive sheet 5 in accordance with ameasured value obtained by using means 34 for measuring tensions of theadhesive sheet 5 around the semiconductor chip 2 to be separated,measuring the sheet tensions, and upthrowing them in the controller 30.

Thus, by using a function for measuring tensions of the adhesive sheet 5produced when upthrowing is performed by the upthrow jig 11 andultrasonic vibration is applied and controlling the tensions, it ispossible to obtain a thin semiconductor device having no imperfectseparation.

When separating and picking up the semiconductor chip 2 by the chipseparating unit of this embodiment 1, it is preferable to set a function(retry function) for applying the same separating operation again to thesemiconductor chip 2 failing in chip separation from the adhesive sheet5 at the first-time separating operation. It is preferable to provide anoperation sequence for not performing separating operation any more whenseparation cannot be performed again for this function.

The following is the separation processing using the function.

Firstly, the pickup stage 8 is moved to move the semiconductor chip 2 tobe separated to the position immediately above the upthrow jig 11. Thesemiconductor chip 2 to be separated vacuum-sucks the sheet backside bythe vacuuming stage 15. The vacuum-sucking of the vacuuming collet 16 isoperated to lower the vacuuming collet 16. While vacuuming and holdingthe adhesive sheet 5, the upthrow jig 11 is raised to upheave thesemiconductor chip 2 through the adhesive sheet 5. After upheaving thesemiconductor chip 2, by applying ultrasonic vibration to the upthrowpin 11 and the semiconductor chip 2 through the sheet 5, thesemiconductor chip 2 is separated from the sheet and vacuumed and heldby the vacuuming collet 16 to raise the vacuuming collet 16. The qualityof chip separation is determined by using a function for measuring thevacuuming pressure or vacuuming flow rate of the vacuuming collet 16 ora function for determining presence or absence of a chip by setting asensor to a vacuuming hole of the vacuuming collet 16. When thesemiconductor chip 2 is not vacuumed by the vacuuming collet 16, thenumber of retry times is counted by a counter or the like. The sameseparating operation is applied to the semiconductor chip 2 again whichcannot be separated from the adhesive sheet 5. However, when thesemiconductor chip 2 cannot be still separated after applying theseparating operation to the chip again, the separating operation is notapplied any more to the semiconductor chip 2 which cannot be separatedagain but another semiconductor chip 2 is separated by canceling vacuumstates of the vacuuming collet and vacuuming stage.

In this case, the semiconductor chip 2 which cannot be separated throughthe second-time separating operation, the adhesive force of, forexample, the adhesive agent layer is not deteriorated, or a chip whichcannot be separated due to the reason such as imperfect upthrowing in adicing step is brought into a specific state and therefore, it cannot beseparated at a high probability even if retry is performed again.Moreover, the number of opportunities for providing a damage for thesemiconductor chip 2 is increased by repeating separating operation aplurality of times and thereby applying ultrasonic vibration to thesemiconductor chip 2 and adhesive sheet 5 by the number of repetitiveseparating operations. Therefore, it is preferable that separatingoperation is not applied to one chip three times or more.

By restricting the number of retries for performing separating operationagain to a semiconductor chip which cannot be separated, it is possibleto obtain a thin semiconductor device having no damage due toseparation.

FIG. 12 is a sectional view showing a chip separating unit used for afabrication method of a semiconductor device of second embodiment 2.

In the case of the chip separating unit of embodiment 1, the vibrationdirection and amplitude direction of the ultrasonic wave is vertical tothe semiconductor chip 2. However, as shown in FIG. 12, it is allowed touse a device configuration for applying horizontal-directionalultrasonic vibration to the semiconductor chip 2. Also when thevibration direction is horizontal, the chip separating operation has thesame operation procedure as the case of above embodiment 1.

A semiconductor chip 2 to be separated is upheaved through a adhesivesheet 5 by vacuuming the back of the adhesive sheet 5 by a vacuumingstage 15 and raising an upthrow jig 12 while holding the adhesive sheet5. After upheaving the semiconductor chip 2, the horizontal-directionalultrasonic vibration having a frequency of 20 to 80 kHz and an amplitudeof 20 to 80 μm is applied to the upthrow jig 12 and the semiconductorchip 2 through the adhesive sheet 5, it is possible to separate thesemiconductor chip 2 from the adhesive sheet 5. In this case, as shownin FIG. 4, when the semiconductor chip 2 is upheaved by the upthrow jig12 through the adhesive sheet 5, a tension is produced in the sheet basematerial 4 of the adhesive sheet 5, the adhesive agent layer 3 presentat the boundary between the base material 4 and the chip 2 is expanded,and an adhesive agent layer 3 a on the outer periphery of thesemiconductor chip 2 is most expanded. When vibrating the upthrow jig 12at a high speed in the horizontal direction under the above state, theadhesive agent layer 3 is repeatedly extended and contracted at a highspeed, a fatigue failure occurs in the adhesive agent layer 3, thefailure is progressed, and the semiconductor chip 2 is separated fromthe adhesive agent layer 3. Moreover, by applying the ultrasonicvibration to the upthrow jig 12, the upthrow jig 12 is heated up toseveral tens of degrees. However, by pressing the tip end of the heatedupthrow jig 12 against the adhesive sheet 5 to which the semiconductorchip 2 to be separated is attached, the adhesive sheet 5 is expanded andcontracted and thereby, the semiconductor chip 2 becomes easily removed.Furthermore, because friction heat is produced by rubbing the back ofthe adhesive sheet 5 at a high speed and the adhesive sheet 5 isexpanded and contracted, the semiconductor chip 2 becomes easilyremoved.

Furthermore, the same advantage can be obtained from a vibration methodfor changing angles for setting an upthrow jig and ultrasonic waveoscillator and tilting a vibration direction. Furthermore, the sameadvantage can be obtained from a two-dimensional vibration direction inwhich vertical and horizontal directional vibrations are compounded.

FIG. 13 is a sectional view showing a chip separating unit used for afabrication method of a semiconductor device of embodiment 3 of thepresent invention.

In the case of the chip separating unit of embodiment 1, the upthrow jig11 is set to the ultrasonic wave oscillator 17 having built-inpiezoelectric device 18 to use the upthrow jig 11 so that the aperturedimension and shape of the jig 11 can be changed or the frequency andamplitude of ultrasonic vibration can be changed in accordance with thesize of the semiconductor chip 2 to be separated. However, it is alsoallowed to use a device for separating the semiconductor chip 2 by thesingle piezoelectric device 18 not through the upthrow jig 11.

The chip separating unit of embodiment 3 separates a chip in accordancewith the same operation procedure as embodiment 1. A semiconductor chip2 to be separated is upheaved by the tip end of a piezoelectric device18 through an adhesive sheet 5 by vacuuming the back of the sheet by avacuuming stage 15 and raising the piezoelectric device 18 while holdingthe adhesive sheet 5. After upheaving the semiconductor chip 2, thesemiconductor chip 2 is separated from the adhesive sheet 5 by supplyinga current to the piezoelectric device 18 and applying ultrasonicvibration to the semiconductor chip 2 through the adhesive sheet 5. Inthis case, the piezoelectric device is selected so that the tip endthereof generates vibration of a frequency of 20 to 80 kHz and anamplitude of 20 to 80 μm.

FIG. 14 is a sectional view showing a chip separating unit used for afabrication method of a semiconductor device of embodiment 4.

In the case of the chip separating unit of embodiment 1, thesemiconductor chip 2 attached to the adhesive sheet 5 is separated byraising the upthrow jig 11 from the backside of the sheet. However, itis also allowed to separate the semiconductor chip 2 by a deviceconfiguration in which all constituting devices are vertically reversed.

A chip separating unit of embodiment 4 has a pickup stage 8 forsupporting an adhesive sheet 5 to which a semiconductor chip 2 havingexperienced a dicing step is attached and a frame 7 and performinghorizontal movement and positioning, a vacuuming stage 15 located abovethe pickup stage 8 to vacuum the back of the adhesive sheet 5, anupthrow jig 11 located so as to be able to raise or lower a upthrow hole13 at the center of the vacuuming stage to upthrow the adhesive sheet 5and semiconductor chip 2, an ultrasonic oscillator 17 having a built-inpiezoelectric device 18 for generating ultrasonic vibration in theupthrow jig 11 below the upthrow jig 11, and a vacuuming collet 16 forvacuuming and holding the separated semiconductor chip 2 and carryingand mounting it to and on the next step below the pickup stage 8.

Firstly, the semiconductor chip 2 attached onto the adhesive sheet 5fixed to the frame 7 is fixed to the pickup stage 8 is fixed so that thecircuit pattern face of the semiconductor chip 2 is turned downward. Thesemiconductor chip 2 to be separated is pressed by the tip end of theupthrow jig 11 through the adhesive sheet 5 by vacuuming the back of thesheet by the vacuuming stage 15 and lowering the upthrow jig 11 whileholding the sheet 5. After lowering the upthrow jig 11 by apredetermined value, the tip end of the upthrow jig 11 appliesultrasonic vibration having a frequency of 20 to 80 kHz and an amplitudeof 20 to 80 μm to the semiconductor chip 2 through the adhesive sheet 5and thereby, it is possible to separate the semiconductor chip 2 fromthe adhesive sheet 5. When picking up the semiconductor chip 2, theseparated semiconductor chip 2 previously moves the vacuuming collet 16to a predetermined height immediately below the semiconductor chip 2 tobe separated, and raises and positions the semiconductor chip 2, andvacuums and holds the chip 2 on the circuit pattern face by thevacuuming collet 16 while its vacuum-sucking is turned on. Then, theback of the chip is vacuumed and held by another not-illustratedvacuuming collet to mount the chip on a chip arranging vessel (tray) ormount it on a substrate on which a device will be mounted so as to turnthe circuit pattern face of the chip downward.

Moreover, it is allowed to use a chip separating unit for setting a chiparranging vessel provided with a mechanism capable ofthree-dimensionally moving below the semiconductor chip 2, raising thevessel up to a height close to the chip, and directly mounting the chipseparated by ultrasonic vibration on the vessel while the circuitpattern face is turned downward.

Thus, by using the vertically-reversed device configuration, it ispossible to obtain a thin semiconductor device capable of supplying thecircuit patter face of a semiconductor chip so as to be turned downward.

FIG. 15 is a sectional view showing a chip separating unit use for afabrication method of a semiconductor device of embodiment 5, and FIGS.16(a) to 16(c) are illustrations respectively showing an example of amoving track of the upthrow jig of the embodiment 5.

The chip separating unit of embodiment 1 uses the elevating operation byonly one axis for raising the upthrow jig 11 up to a predeterminedvalue, applying ultrasonic vibration to the upthrow jig 11 for apredetermined time, and lowering the upthrow jig 11 up to the initialposition after the vibration is completed. However, it is also allowedto use a mechanism for raising the upthrow jig 11 and moving the upthrowjig 11 into the horizontal face of the semiconductor chip 2 whileapplying the ultrasonic vibration to the upthrow jig 11.

As shown in FIG. 15, the chip separating unit of the embodiment 5upheaves a semiconductor chip 2 to be separated through an adhesivesheet 5 by vacuuming the back of the adhesive sheet 5 by a vacuumingstage 15 and raising the upthrow jig 11 while vacuuming and holding thesheet 5. After upheaving the chip 2, ultrasonic vibration having afrequency of 20 to 80 kHz and an amplitude of 20 to 80 pn to the upthrowjig 11 is applied. In this case, the upthrow jig 11 to which theultrasonic vibration are applied is moved in the horizontal plane of thesemiconductor chip 2 by a two-axes moving mechanism 25 to separate thechip. As shown in FIG. 16, the moving track of the tip end of theupthrow jig 11 shows a linear movement at the diagonal line of thesemiconductor chip 2 (FIG. 16(a)), linear movement passing through thecenter of the semiconductor chip 2 (FIG. 16(b)), circular movementnearby the outer periphery and four corners of the semiconductor chip 2(FIG. 16(c)), or irregular movement in the horizontal face of thesemiconductor chip 2.

Thus, by moving the upthrow jig 11 to which the ultrasonic vibration isapplied in the horizontal face of the semiconductor chip 2, it ispossible to easily separate the semiconductor chip 2 without changingthe upthrow jig 11 independently of the size of the semiconductor chip2.

FIG. 20 is a sectional view showing an example of the configuration of achip separating unit used for a fabrication method of a semiconductordevice which is of embodiment 6 of the present invention, and FIGS.21(a) and 21(b) are sectional views showing an example of the upthrowoperation of the chip separating unit of embodiment 6 in order of thesteps.

The chip separating unit of embodiment 6 has a pickup stage 100100 forsupporting an adhesive sheet 1005 having experienced a dicing step and ametallic frame 1007 to perform the horizontal positioning operation, avacuuming stage 10015 located below the pickup stage 100100, an upthrowpin 10011 set to the position of a window hole 10013 vertically movablyopened on an ultrasonic wave portion of the vacuuming stage 10015, andan ultrasonic oscillator 10017 for supporting the upthrow pin 10011 toapply ultrasonic vibration to the upthrow pin 10011.

A plurality of vacuuming holes 10014 communicating with an externalvacuuming mechanism are opened at the upside of the vacuuming stage10015 facing the backside of an adhesive sheet 1005 so that the vacuumholding and vacuum canceling operations of the adhesive sheet 1005around a window hole 10013 can be performed.

Moreover, the ultrasonic vibrator 10017 supporting the upthrow pin 10011is supported by a not-illustrated vertical-movement mechanism and canperform a vertical movement independently of the vacuuming stage 10015so that the upthrow operation can be performed by the upthrow pin 10011.

A vacuuming collet 10016 supported by a not-illustratedthree-dimensional movement mechanism is set above the pickup stage100100 so as to be able to move onto the position immediately above eachof a plurality of semiconductor chips 1002 attached to the adhesivesheet 1005 supported by the metallic frame 1007 to position it and carryan vacuumed and held semiconductor chip 1002 to the outside.

A vacuuming hole 10016 a communicating with an external vacuumingmechanism is opened at the bottom end (tip end) of the vacuuming collet10016 so that the vacuum holding and hold canceling operations of thesemiconductor chips 1002 can be performed by turning on/off thevacuuming operation to the vacuuming hole 10016 a from the vacuumingmechanism.

In the pickup step in which cut thin and small semiconductor chips 1002attached onto the adhesive sheet 1005, whose adhesive strength isdeteriorated, are separated from the adhesive sheet 1005, the metallicframe 1007 and adhesive sheet 1005 are first moved so that thesemiconductor chips 1002 to be separated are brought to predeterminedpositions. The back of the adhesive sheet of the semiconductor chips1002 to be separated is vacuum-sucked by a vacuuming hole 10014 of thevacuuming stage 10015 to vacuum and hold the adhesive sheet 1005. Inthis case, the window hole 10013 has a size corresponding to one of thesemiconductor chips 1002 and vacuums the adhesive sheet portion to whichthe semiconductor chips other than those to be separated are attached.

As described above, the upthrow pin 10011 for upthrowing thesemiconductor chips 1002 is set below the vacuuming stage 10015, and theupthrow pin 10011 is vertically moved by motor driving and pneumaticdriving. The ultrasonic vibrator 10017 is built in below the aboveupthrow pin 10011 (horn), and although not illustrated, an ultrasonicoscillator is connected to the ultrasonic vibrator 10017 so that the tipend of the upthrow pin 10011 generates ultrasonic vibration.

Operations of the chip separating unit of this embodiment 6 aredescribed below.

When picking up the semiconductor chips 1002, the vacuuming collet 10016is positioned to a predetermined height immediately above thesemiconductor chips 1002 to be separated, and the vacuuming stage 10015is positioned so that the window hole 10013 coincides with the positionimmediately below a purposed semiconductor chip 1002 to be separated andthen, the back of the sheet around the window hole 10013 isvacuum-sucked by the vacuuming stage 10015 and then the upthrow pin 1011is raised while holding the adhesive sheet 1005 to upheave thesemiconductor chips 1002 through the adhesive sheet 1005 (FIG. 21(a)).

The height of the vacuuming collet 10016 is set to a height close to thesemiconductor chips 1002 without contacting the upside of thesemiconductor chips 1002 in the upthrown state by the upthrow pin 10011.

The upheaving value (amount) of the upthrow pin 10011 is set to 10 to200 μm on the basis of the upside of the vacuuming stage 10015 (downsideof the adhesive sheet 1005) to be an upheaving value so as not to breakthe adhesive sheet 1005. However, because the elongation amount of thesheet depends on the adhesive sheet 1005 used, the elongation amount isnot restricted to the above upheaving value.

Moreover, in the case of this embodiment 6, the tip end shape of theupthrow pin 10011 is formed into a flat or circular-arc pin. By usingthis shape, the adhesive sheet 1005 is not easily broken when upheavingthe upthrow pin 10011, and the heat due to ultrasonic vibration iseasily propagated. The size of the circular arc and the angle of the tipend are set in accordance with the characteristic of an adhesive sheetused.

After raising the upthrow pin 10011 up to a predetermined value,longitudinal ultrasonic vibration is applied to the semiconductor chips1002 from the ultrasonic vibrator 10017 through the adhesive sheet 1005so that the tip end of the upthrow pin 10011 has a frequency of 10 to100 kHz and an amplitude of 10 to 50 μm and thereby the semiconductorchips 1002 are removed from the adhesive sheet 1005 (FIG. 21(b)).

Then, in the case of this embodiment 6, by applying ultrasonic vibrationto the flexible adhesive sheet 1005 and the semiconductor chips 1002respectively having a large stiffness, the adhesive sheet 1005 causes atension change, the portion of the adhesive agent layer 1003 is brokenat the interface between the adhesive sheet 1005 and the semiconductorchips 1002 having physical properties including stiffness different fromeach other, and the semiconductor chips 1002 become easily removed fromthe adhesive sheet 1005. That is, it is possible to efficiently removethe semiconductor chips 1002 in a short time at a very high energycompared to the case of providing mechanical slides of several times forthe adhesive sheet 1005 like the case of the prior art.

Moreover, by applying an ultrasonic wave to the upthrow pin 10011, thetip end of the upthrow pin 10011 is heated up to several tens ofdegrees. However, by pressing the heated tip end of the pin against theadhesive sheet 1005 to which the semiconductor chips 1002 to beseparated are attached, the adhesive sheet 1005 is expanded andcontracted and thereby, the semiconductor chips 1002 are more easilyremoved in cooperation with the effect of the above ultrasonicvibration.

The semiconductor chips 1002 removed from the adhesive sheet 1005 aremoved to and vacuumed and held by the vacuuming collet 10016 by thevacuuming force of the vacuuming collet 10016 separated from and locatedat the position immediately above the adhesive sheet 1005 and mounted ona substrate 10019 on which a device will be mounted such as a lead frameon a bonding stage 100200. In this case, the timing for the vacuumingcollet 10016 to vacuum the semiconductor chips 1002 may be before orafter providing the ultrasonic vibration.

The linked operation of each section of the chip separating unit of thisembodiment 6 is performed in accordance with the timing chart in FIG. 9.

In the case of this embodiment 6, the removal is performed by usingultrasonic vibration in accordance with the vertical movement of thesingle upthrow pin 10011. Therefore, just by changing the aperturedimension and shape of the upthrow pin 10011 in accordance with the sizeof the semiconductor chip 1002, the upthrow pin 10011 can be applied topickup of all sizes of the semiconductor chips 1002, from acomparatively large size to a thin small size having a side of severalmillimeters or less, and it is possible to obtain a semiconductor deviceconstituted by the semiconductor chips 1002 of all sizes respectivelyhaving no scratch on the backside.

As a modification of this embodiment 6, the removal is performed byusing ultrasonic vibration in accordance with the vertical movement ofthe signal upthrow pin 10011, however, when a semiconductor chip islarge, it is also possible to use a chip separating unit for removing asemiconductor chip to be removed by setting a plurality of upthrow pinsin the area of the semiconductor chip to be removed, simultaneouslyupthrowing the semiconductor chip, and applying an ultrasonic wave tothem.

As a modification of this embodiment 6, only one chip is removed byusing the ultrasonic vibration in accordance with the vertical movementof the signal upthrow pin 10011. However, it is also possible to use aplurality of chip separating units same as the chip separating unitshown in FIG. 20 for simultaneously removing a plurality ofsemiconductor chips by setting the chip separating units in the samewafer.

As a modification of this embodiment 6, the ultrasonic vibration isapplied to the upthrow pin 10011 after the upthrow pin is raised.However, it is also possible to use a procedure for upheaving theupthrow pin 10011 while applying ultrasonic vibration to the upthrow pinby considering the continuous oscillation performance of the ultrasonicwave and the exothermic theory of the ultrasonic wave inversely to theabove mentioned one as the timing for oscillating the ultrasonic wave(start timing in the broken-line graph 45 a in FIG. 9).

In the above description, a vibration direction and amplitude directionof the ultrasonic wave applied to the upthrow pin 10011 arelongitudinal. As shown in FIG. 22, however, it is also allowed to applya horizontal ultrasonic vibration to the upthrow pin 10012. Even whenchanging the vibration direction to the horizontal direction, a chipseparating operation conforms to the same operation procedure as withthe case of FIG. 20.

The semiconductor chip 1002 to be separated is upheaved through theadhesive sheet 1005 by vacuuming the backside of the sheet by thevacuuming stage 10015 and raising the upthrow pin 10012 while holdingthe adhesive sheet 1005. After upheaving the semiconductor chip 1002, ahorizontal ultrasonic vibration having a frequency of 10 to 100 kHz andan amplitude of 10 to 50 μm is applied to the upthrow pin 10012 and theultrasonic vibration is applied to the semiconductor chip 1002 throughthe adhesive sheet 1005, and thereby the semiconductor chip 1002 a isremoved from the adhesive sheet 1005. In this case, by applying theultrasonic vibration in the horizontal direction while upheaving thesemiconductor chip 1002 by the upthrow pin 10012 through the adhesivesheet 1005 to firstly rub the back of the sheet, a tension change occursin the adhesive sheet 1005, so that the portion of the adhesive agentlayer 1003 contacting with the semiconductor chip 1002 of the adhesivesheet 1005 is broken, and the semiconductor chip 1002 is easily removed.Moreover, by heating the tip end of the upthrow pin 10012 by anultrasonic wave and rubbing the back of the sheet, friction heat isgenerated and the adhesive sheet 1005 is expanded and contracted, andthereby the semiconductor chip 1002 can be easily removed.

In addition to the above mentioned one, the same advantage can beobtained by a vibration method for tilting a vibration direction bychanging a setting angle of the upthrow pin 10012 to the ultrasonicvibrator 10017.

Then, a fabrication method of a semiconductor device which is embodiment7 of the present invention is described below in detail. FIG. 23 is asectional view showing a chip separating unit used for the fabricationmethod of the semiconductor device of this embodiment 7 and FIGS. 24(a)and 24(b) are sectional views showing an example of the upthrowoperation of this embodiment 7 in order of the steps.

Similarly to the above embodiment 6, a backside of an adhesive sheet1005 to which semiconductor chips 1002 are attached is vacuumed by thevacuuming hole of a vacuuming stage 10015 to vacuum and hold theadhesive sheet 1005. In this case, a window hole 10013 has a sizecorresponding to one of the semiconductor chips 1002 to vacuum theadhesive sheet portion to which the semiconductor chips 1002 other thanthose to be separated are attached.

In the case of the embodiment 7, an upthrow pin 10021 for upthrowing thesemiconductor chips 1002 is set below the vacuuming stage 10015 toperform vertical movement through motor driving and pneumatic driving. Ahigh-speed rotational motor 10027 for rotating the upthrow pin 10021 isset below the upthrow pin 10021. An eccentric pin 10022 is provided inan eccentric position at the tip end of the upthrow pin 10021.

According to the configuration in which the eccentric pin 10022 is setin the eccentric position at the tip end of the upthrow pin 10021, amechanism is obtained, in which the eccentric pin 10022 at the tip endeccentrically whirls so as to draw a circle when the upthrow pin 10021rotates at a high-speed.

The front-end shape of the eccentric pin 10022 is formed into acircular-arc pin. According to this shape, the adhesive sheet 1005 isnot easily broken when upheaving the eccentric pin 10022, and thefriction heat generated when the whirling eccentric pin 10022 rubs iseasily propagated. The size of the circular arc at the tip end of theeccentric pin 10022 is set in accordance with the characteristic of theadhesive sheet 1005 used.

The semiconductor chip 1002 to be separated is upheaved through theadhesive sheet 1005 by vacuuming the back of the adhesive sheet 1005 bythe vacuuming stage 10015, and raising the upthrow pin 10021 (eccentricpin 10022) while holding the adhesive sheet 1005. The upheaving value(amount) of the upthrow pin 10021 (eccentric pin 10022) is set to 10 to200 μm on the basis of the upside of the vacuuming stage 10015 so as notto break the adhesive sheet 1005. However, because the elongation of asheet base material 1004 depends on the adhesive sheet 1005 used, theabove upheaving value is not restricted.

By raising the upthrow pin 10021 (eccentric pin 10022) up to apredetermined value and rotating the upthrow pin 10021 at a high speed,the eccentric pin 10022 set in an eccentric position whirls so as todraw a circle and slides on the downside of the adhesive sheet 1005. Therotational speed of the eccentric pin 10022 (upthrow pin 10021) is setat 1,000 to 30,000 rpm. Thus, by rubbing the adhesive sheet 1005 towhich the semiconductor chips 1002 are attached by the eccentricallywhirling eccentric pin 10022 at a high speed, the semiconductor chips1002 are easily removed from the adhesive sheet 1005 in a short time.

In this case, it is preferable to set the offset value ΔR (turningradius) between the upthrow pin 10021 and eccentric pin 10022 in a rangefrom the half of a side of a semiconductor chip 1002 to be separated(FIG. 29(a)) to the half of the diagonal length of the semiconductorchip 1002 (FIG. 29(b)). According to this structure, the tip end of theeccentric pin 10022 eccentrically whirling at the offset value ΔR rubs aportion near four sides of the semiconductor chip 1002 as shown in FIG.29(a) or rubs by passing through the portion near four corners as shownin FIG. 29(b) and the semiconductor chip 1002 is easily removed due to atension change of the adhesive sheet 1005 and breakage of the portion ofthe adhesive agent layer 1003 of the adhesive sheet 1005. This isbecause, when the vicinity of an end of a semiconductor chip 1002attached to the adhesive sheet 1005 is removed, the whole is easilyremoved by using the removed portion as a start point. Moreover, byrubbing the back of the sheet by the eccentric pin 10022, the adhesivesheet 1005 has a friction heat and the sheet base material 1004 is moreeasily removed because the material 1004 causes a thermal deformationdue to expansion and contraction.

The semiconductor chip 1002 removed from the adhesive sheet 1005 isseparated from the adhesive sheet 1005 by a vacuuming collet 10016, andmounted on a substrate 10019 on which a device will be mounted. In thiscase, it is allowed to set the timing for the vacuuming collet 10016 tovacuum the semiconductor chip 1002 to the timing before or afterrotating the upthrow pin 10021 (eccentric pin 10022).

By eccentrically rotating the pin and using a removal mechanism by theeccentric pin 10022 for rubbing the vicinity of a chip end, it ispossible to obtain a semiconductor device having no scratch on the backof the semiconductor chip 1002 independently of the size of thesemiconductor chip 1002, without breaking the adhesive sheet 1005. Thatis, by setting the apertures of the upthrow pin 10021 and eccentric pin10022 and the offset value ΔR of the eccentric pin 10022 in accordancewith the size of the semiconductor chip 1002, it is possible toeffectively rub four sides and four corners of the semiconductor chip1002 by the eccentric pin 10022 and use the above mentioned for a stepof removing the semiconductor chips 1002 of all sizes from a thin smallsemiconductor chip 1002 up to a comparatively large semiconductor chip1002.

As a modification of this embodiment 7, as shown as the graph 45 in FIG.9, the timing for rotating the eccentric pin 10022 at a high speedrotates the eccentric pin 10022 (timing of the graph 45) after upheavingthe upthrow pin 10021 in the case of the above description. However, itis also allowed to use a procedure for upheaving the upthrow pin 10021while rotating the eccentric pin 10022 at a high speed inversely to theabove mentioned (timing of the graph 45 shown by a broken line).Moreover, the continuous time T of eccentric rotation can be set to avalue almost equal to the longitudinal or transverse moving time Tdescribed for another embodiment.

In addition to the abode description, the same effect can be obtained bya method for changing the setting angle of the upthrow pin 10021,tilting the upheaving direction, and whirling the eccentric pin 10022 ata high speed.

Moreover, it is allowed to set not only one eccentric pin 10022 but alsoa plurality of eccentric pins 10022 having offset values ΔR differentfrom each other to the tip end of the upthrow pin 10021.

Furthermore, it is allowed to obtain the same effect as the case ofhigh-speed whirling of the eccentric pin 10022 by rotating the upthrowpin 10021 whose tip end is formed to be irregular, instead of theeccentric pin 10022.

Then, a fabrication method of a semiconductor device, which isembodiment 8 of the present invention, is described below in detail.FIG. 25 is a sectional view showing a chip separating unit used for thefabrication method of the semiconductor device of this embodiment 8, andFIGS. 26(a) and 26(b) are sectional views showing an example of theupthrow operation of this embodiment 8 in order of the steps.

Similarly to the case of the above embodiment 6, the back of an adhesivesheet 1005 to which semiconductor chips 1002 are attached isvacuum-sucked through a vacuuming hole 10014 of a vacuuming stage 10015to vacuum and hold the adhesive sheet 1005. In this case, a window hole10013 has a size corresponding to one of the semiconductor chips 1002 tovacuum the portion of the adhesive sheet 1005 to which semiconductorchips 1002 other than that to be separated are attached. An upthrow pin10031 for upthrowing the semiconductor chips 1002 is set below avacuuming stage 10015 to perform vertical movement in accordance withmotor driving and pneumatic driving.

In the case of this embodiment 8, a heater 10037 is set to the upthrowpin 10031 so that the tip end of the upthrow pin 10031 is controlled tobe at a necessary temperature. In this case, the tip end of the upthrowpin 10031 is formed into a flat shape or circular-arc shape. Accordingto this shape, the adhesive sheet 1005 is not easily broken whenupheaving the upthrow pin 10031 and heat is easily propagated. The sizeand the circular arc at the tip end of the upthrow pin 10031 and the tipend angle are set in accordance with the characteristic of the adhesivesheet 1005 used.

The front-end temperature of the upthrow pin 10031 controlled by theheater 10037 is set at a temperature at which chips are not thermallybroken or a temperature at which an adhesive sheet is expanded orcontracted due to heat, for example, set at 50 to 80° C. Thesemiconductor chip 1002 to be separated is upheaved through the adhesivesheet 1005 by vacuuming the back of the sheet by the vacuuming stage10015 and raising the upthrow pin 10031 when the tip end of the upthrowpin 10031 reaches a predetermined temperature while holding the adhesivesheet 1005. The upheaving value of the upthrow pin 10031 is set to 10 to200 μm on the basis of the upside of the vacuuming stage 10015 so as notto break the adhesive sheet 1005. Thus, by heating the back of theadhesive sheet 1005 by the tip end of the upthrow pin 10031, theadhesive sheet 1005 is thermally deformed such that expansion orcontraction and the semiconductor chips 1002 are easily removed.Moreover, the adhesive strength of the adhesive agent layer 1003 of theadhesive sheet 1005 is weakened through heating, and the semiconductorchips 1002 are easily removed. The front-end temperature of the upthrowpin 10031 is properly set in accordance with characteristics of theadhesive sheet 1005, such as the deformed value of a sheet base material1004 due to heat and the adhesive strength of the adhesive agent layer1003.

The semiconductor chips 1002 removed from the adhesive sheet 1005 areseparated from the adhesive sheet 1005 by the vacuuming collet 10016 andmounted on a substrate 10019 on which a device will be mounted throughbonding. In this case, it is allowed to set the timing for the vacuumingcollet 10016 to vacuum-suck the semiconductor chips 1002 into the timingbefore or after upheaving the upthrow pin 10031.

Thus, by using a removal mechanism according to the upthrow operation ofthe upthrow pin 10031 whose tip end is heated, it is possible to obtaina semiconductor device having no scratch on the back of thesemiconductor chip 1002 without breaking the adhesive sheet 1005.Moreover, just by setting the shape and aperture dimension of the tipend portion of the upthrow pin 10031 in accordance with the size of thesemiconductor chip 1002, this can be applied to semiconductor chips 1002of all sizes, from a large semiconductor chip 1002 up to a thin smallsemiconductor chip 1002.

For example, in the above description, the heating temperature of thetip end of the upthrow pin 10031 is described. However, it is possibleto properly set the heating temperature in a range in which thesemiconductor chip 1002 is not thermally broken or in accordance withthe characteristic of the adhesive sheet 1005.

Moreover, while depending on the characteristic of the adhesive agentlayer 1003 of the adhesive sheet 1005, it is allowed to separate thesemiconductor chip 1002 by selectively cooling only the contact portionof the semiconductor chip 1002 to be removed on the adhesive sheet 1005and lowering the adhesive strength.

Furthermore, in the case of the above mentioned one, the upthrow pin10031 is heated so that the tip end of the pin 10031 reaches apredetermined temperature before upheaving the pin 10031. However, it isallowed to use a procedure for upheaving the upthrow pin 10031 and thenheating the pin 10031 so that the tip end of the pin 10031 reaches apredetermined temperature inversely to the above mentioned case.However, the upthrow pin 10031 uses a material having a high heatconductivity so that the tip end of the pin 10031 is instantaneouslyheated.

Then, a fabrication method of a semiconductor device, which isembodiment 9 of the present invention, is described below in detail.FIG. 27 is a sectional view showing a chip separating unit used for thefabrication method of the semiconductor device of this embodiment 9.

A pickup stage 100100 supporting a metallic frame 1007 and an adhesivesheet 1005 is moved and positioned so that a semiconductor chip 1002 tobe separated reaches a predetermined position. A screening jig 10045 onwhich a window hole 10045 a almost equal to a chip size is opened is setbelow the semiconductor chip 1002 to be separated so as to applyultraviolet radiation UV from a UV applying unit 10041 at the bottom.According to this mechanism, only an adhesive agent layer 1003 of theadhesive sheet 1005 of the semiconductor chip 1002 to be separated isselectively cured so that the semiconductor chip 1002 is easily removed.Then, the semiconductor chip 1002 which is easily removed from theadhesive sheet 1005 is separated from the adhesive sheet 1005 by avacuuming collet 10016 and mounted on a substrate 10019 on which adevice will be mounted. In this case, it is allowed to set the timingfor the vacuuming collet 10016 to vacuum the semiconductor chip 1002 tothe timing before or after applying ultraviolet radiation UV to theadhesive sheet 1005.

By using an upthrow-pin-less removal mechanism for selectively applyingultraviolet radiation UV immediately before performing pickup andlowering the adhesive strength of the adhesive sheet 1005 without usingan upthrow pin, it is possible to obtain a semiconductor device havingno scratch on the back of the semiconductor chip 1002 without breakingthe adhesive sheet 1005.

Moreover, by setting the aperture dimension of the window hole 10045 aopened on the screening jig 10045 in accordance with the size of thesingle semiconductor chip 1002, this can be applied to removal of allsemiconductor chips 1002, from a semiconductor chip of comparativelylarge size up to a thin and small semiconductor chip 1002.

However, when using this separation method, it is necessary to use theadhesive agent layer 1003 whose adhesive strength becomes almost zero byirradiating ultraviolet radiation UV as the adhesive agent layer 1003 onthe adhesive sheet 1005 used and the adhesive sheet 1005.

FIG. 28 is a sectional view showing a modification of this embodiment 9.In the above description, the screening jig 10045 on which the windowhole 10045 a having the same size as a chip is opened is set below thesemiconductor chip 1002 to be separated to selectively apply ultravioletradiation UV from the window hole 10045 a at the bottom. However, byusing a spot UV applying unit 10042 capable of applying the ultravioletradiation UV converged like a spot, a method can be used which separatesthe semiconductor chip 1002 to be separated of the adhesive sheet 1005by using a more simplified device configuration and selectively applyingthe ultraviolet radiation UV only to a contact portion of thesemiconductor chip 1002 to be separated on the adhesive sheet 1005 andlowering the adhesive strength without using a component such as thescreening jig 10045.

Moreover, it is allowed to use a method for accelerating removal byapplying a laser beam 10050 only to a contact portion of thesemiconductor chip 1002 to be separated on the adhesive sheet 1005instead of ultraviolet radiation UV and selectively applying energy suchas instantaneous heating.

In this case, as shown in FIG. 27, it is possible to use a method forselectively applying a broad laser beam 10050 only to a contact portionof the semiconductor chip 1002 to be separated on the from the windowhole 10045 a by using a laser beam source 10051 for emitting the laserbeam 10050 and the screening jig 10045 together or as shown in FIG. 28,a method for selectively applying ultraviolet radiation UV only to acontact portion of the semiconductor chip 1002 to be separated by usinga spot laser beam source 10052 for emitting a spot-like laser beam 10050without using the screening jig 10045.

Moreover, it is allowed to use removal acceleration by the heatingeffect by applying a microwave only to a contact portion of thesemiconductor chip 1002 to be separated on the adhesive sheet 1005instead of ultraviolet radiation UV.

In the case of the fabrication method of the semiconductor device ofthis embodiment, the back of the semiconductor chip 1002 (semiconductordevice) is not damaged at all in the pickup step as described above.Therefore, the reliability of the semiconductor chips 1002 is improved,the number of defective products due to damages of the semiconductorchips 1002 is greatly decreased, and the manufacturing yield ofsemiconductor devices is improved. Moreover, it is possible to quicklypick up semiconductor chips of all sizes, from a large semiconductorchip to a thin and small semiconductor chip, by using a chip separatingunit having a simple configuration and contribute to reduction of thecost and improvement of the throughput in the fabrication process.

The invention made by the present inventor is specifically described inaccordance with embodiments. However, the present invention is notrestricted to the embodiments. It is needless to say that variousmodifications of the present invention are allowed as long as they arenot deviated from the gist of the present invention.

What can be said for the embodiments in common is that it is possible toseparate a diced semiconductor chip from an adhesive sheet in picking upthe semiconductor chip without damaging the semiconductor chipindependently of the size of the chip in the assembling process of asemiconductor device.

It is possible to provide a reliable semiconductor device having noscratch on the back of a thin and small semiconductor chip by separatingthe semiconductor chip from an adhesive sheet without breaking theadhesive sheet in the pickup step after dicing the semiconductor chip.

INDUSTRIAL APPLICABILITY

The present invention is an invention relating to the fabrication art inthe semiconductor industry and an invention which can be used forindustries.

1. A method of manufacturing a semiconductor device including a pickupstep of: dicing a semiconductor wafer which has been subjected toback-grinding to have a thickness of 100 μm or less and to which anadhesive sheet is attached, into individual semiconductor chips; andvacuuming each semiconductor chip to hold it using a vacuuming jig tocollect each semiconductor chip from the adhesive sheet, whereinultrasonic vibration is applied to the semiconductor chips through theadhesive sheet in the pickup step.
 2. The method of manufacturing asemiconductor device according to claim 1, wherein said ultrasonicvibration is applied in a direction crossing an adhesive surface betweenthe adhesive sheet and the semiconductor chips, or in a directionparallel with the adhesive surface.
 3. The method of manufacturing asemiconductor device according to claim 1, further including providing ameans for measuring the temperature of the semiconductor chips, theadhesive sheet, or a jig for applying the ultrasonic vibration tocontrol the temperature thereof.
 4. The method of manufacturing asemiconductor device according to claim 1, further including measuringand controlling the tension of the adhesive sheet.
 5. The method ofmanufacturing a semiconductor device according to claim 1, furtherincluding providing a function in which the same separating operation isapplied again to a chip of which separation from the adhesive sheet hasfailed once, but the same separating operation is not applied to thechip any more if the chip cannot be separated two times.
 6. The methodof manufacturing a semiconductor device according to claim 1, furtherincluding supplying the chip so that a circuit pattern surface thereoffaces by reversing the semiconductor wafer upside down.
 7. The method ofmanufacturing a semiconductor device according to claim 1, furtherincluding moving said contact jig for applying the ultrasonic vibrationin a horizontal plane of the semiconductor chip while applying theultrasonic vibration.
 8. A stack-type semiconductor device constitutedby stacking a plurality of semiconductor chips, wherein an adhesivesheet attached to a backside of a functional surface of thesemiconductor chips is removed by applying ultrasonic vibration to useas the semiconductor chips.